How to Bake High Poly Object Details (Shape) to the low poly object?
From experience, I and others will tell you that normal maps work best for details like bumps and crevices. They work very poorly--are unsuitable--for baking a &quot;high poly mesh&quot; whose silhouette is noticeably distorted compared to the original. You are not going to get anything good from that.
What you are trying to do in this example is similar to attempting to make the default cube appear as a uv-sphere (much rounder) just by turning on &quot;smooth shading&quot; for its 8 vertices. The problem is not just how light interacts with the object on its surface (a huge problem in this example), but that the silhouettes will not be changed with a normal map.
If you make both meshes the same shape and sculpt wood grain into the high poly mesh, that is exactly what normal maps are useful for and you can get nice results in Blender.